Code review for recent dbsize changes. Fix some thinkos, enforce coding
authorTom Lane <tgl@sss.pgh.pa.us>
Tue, 28 Sep 2004 19:35:43 +0000 (19:35 +0000)
committerTom Lane <tgl@sss.pgh.pa.us>
Tue, 28 Sep 2004 19:35:43 +0000 (19:35 +0000)
style and message style standards, improve documentation.

contrib/dbsize/README.dbsize
contrib/dbsize/dbsize.c
contrib/dbsize/dbsize.sql.in

index 7ba4ed8ce6e02ac53c88444208e1f296db0f52ec..f1b60de75fcfff576e2a45a834d25ceef5e1a5c1 100644 (file)
@@ -5,8 +5,8 @@ database object:
    int8 relation_size(text)
 
    int8 pg_database_size(oid)
-   int8 pg_tablespace_size(oid)
    int8 pg_relation_size(oid)
+   int8 pg_tablespace_size(oid)
 
    text pg_size_pretty(int8)
 
@@ -15,40 +15,37 @@ The first two functions:
    SELECT database_size('template1');
    SELECT relation_size('pg_class');
 
-take the name of the object, and support databases and tables. Please
-note that relation_size() only reports table file usage and not the
-space used by indexes and toast tables.
-
-Functions using oids are:
+take the name of the object (possibly schema-qualified, for relation_size),
+while these functions take object OIDs:
    
    SELECT pg_database_size(1);         -- template1 database
-   SELECT pg_tablespace_size(1663);    -- pg_default tablespace
    SELECT pg_relation_size(1259);      -- pg_class table size
+   SELECT pg_tablespace_size(1663);    -- pg_default tablespace
 
-pg_relation_size() will report the size of the table, index and toast
-table OIDs, but they must be requested individually. To obtain the total
-size of a table including all helper files you'd have to do something
-like:
-
-XXX This query does not work, syntax error XXX
-   
-   SELECT pg_relation_size(cl.oid) AS tablesize,
-          CASE WHEN reltoastrelid=0 THEN 0
-               ELSE pg_relation_size(reltoastrelid) END AS toastsize,
-          SUM(pg_relation_size(indexrelid)) AS indexsize,
-          pg_size_pretty(pg_relation_size(cl.oid)
-                       + pg_relation_size(reltoastrelid)
-                       + SUM(pg_relation_size(indexrelid))::int8) 
-                               AS totalsize
-     FROM pg_class cl
-     JOIN pg_index ON cl.oid=indrelid
-    WHERE relname = 'pg_rewrite'
-    GROUP BY 1,2
+Please note that relation_size and pg_relation_size report only the size of
+the selected relation itself; any subsidiary indexes or toast tables are not
+counted.  To obtain the total size of a table including all helper files
+you'd have to do something like:
+
+SELECT *,
+    pg_size_pretty(tablesize+indexsize+toastsize+toastindexsize) AS totalsize
+FROM
+(SELECT pg_relation_size(cl.oid) AS tablesize,
+        COALESCE((SELECT SUM(pg_relation_size(indexrelid))::bigint
+                  FROM pg_index WHERE cl.oid=indrelid), 0) AS indexsize,
+        CASE WHEN reltoastrelid=0 THEN 0
+             ELSE pg_relation_size(reltoastrelid)
+        END AS toastsize,
+        CASE WHEN reltoastrelid=0 THEN 0
+             ELSE pg_relation_size((SELECT reltoastidxid FROM pg_class ct
+                                    WHERE ct.oid = cl.reltoastrelid))
+        END AS toastindexsize
+ FROM pg_class cl
+ WHERE relname = 'foo') ss;
 
 This sample query utilizes the helper function pg_size_pretty(int8),
 which formats the number of bytes into a convenient string using KB, MB,
 GB.  It is also contained in this module.
 
-To install, just run make; make install.  Finally, load the functions
+To install, just run make; make install.  Then load the functions
 into any database using dbsize.sql.
-
index 872f0f899a6d02936bb31dadc4962b9236e3d103..e332a62f86dbd5801d77a2140c8e8e8614767da0 100644 (file)
@@ -2,29 +2,29 @@
  * dbsize.c
  * object size functions
  *
- * Copyright (c) 2004, PostgreSQL Global Development Group
+ * Copyright (c) 2002-2004, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/contrib/dbsize/dbsize.c,v 1.14 2004/09/02 04:04:04 momjian Exp $
+ *   $PostgreSQL: pgsql/contrib/dbsize/dbsize.c,v 1.15 2004/09/28 19:35:43 tgl Exp $
  *
  */
 
-
 #include "postgres.h"
 
 #include <sys/types.h>
 #include <sys/stat.h>
 
 #include "access/heapam.h"
-#include "storage/fd.h"
-#include "utils/syscache.h"
-#include "utils/builtins.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_tablespace.h"
 #include "commands/dbcommands.h"
 #include "miscadmin.h"
+#include "storage/fd.h"
+#include "utils/builtins.h"
+#include "utils/syscache.h"
 
 
+/* hack to make it compile under Win32 */
 extern DLLIMPORT char *DataDir;
 
 Datum pg_tablespace_size(PG_FUNCTION_ARGS);
@@ -44,25 +44,26 @@ PG_FUNCTION_INFO_V1(database_size);
 PG_FUNCTION_INFO_V1(relation_size);
 
 
-
+/* Return physical size of directory contents, or 0 if dir doesn't exist */
 static int64
-db_dir_size(char *path)
+db_dir_size(const char *path)
 {
-    int64 dirsize=0;
+   int64       dirsize = 0;
     struct dirent *direntry;
    DIR         *dirdesc;
    char filename[MAXPGPATH];
 
-   dirdesc=AllocateDir(path);
+   dirdesc = AllocateDir(path);
 
    if (!dirdesc)
        return 0;
 
-   while ((direntry = readdir(dirdesc)) != 0)
+   while ((direntry = readdir(dirdesc)) != NULL)
    {
        struct stat fst;
 
-       if (!strcmp(direntry->d_name, ".") || !strcmp(direntry->d_name, ".."))
+       if (strcmp(direntry->d_name, ".") == 0 ||
+           strcmp(direntry->d_name, "..") == 0)
            continue;
 
        snprintf(filename, MAXPGPATH, "%s/%s", path, direntry->d_name);
@@ -82,39 +83,44 @@ db_dir_size(char *path)
 static int64
 calculate_database_size(Oid dbOid)
 {
-   int64 totalsize=0;
+   int64       totalsize = 0;
    DIR         *dirdesc;
     struct dirent *direntry;
    char pathname[MAXPGPATH];
 
-   snprintf(pathname, MAXPGPATH, "%s/global/%u", DataDir, (unsigned)dbOid);
-   totalsize += db_dir_size(pathname);
-   snprintf(pathname, MAXPGPATH, "%s/base/%u", DataDir, (unsigned)dbOid);
+   /* Shared storage in pg_global is not counted */
+
+   /* Include pg_default storage */
+   snprintf(pathname, MAXPGPATH, "%s/base/%u", DataDir, dbOid);
    totalsize += db_dir_size(pathname);
 
+   /* Scan the non-default tablespaces */
    snprintf(pathname, MAXPGPATH, "%s/pg_tblspc", DataDir);
    dirdesc = AllocateDir(pathname);
-
    if (!dirdesc)
        ereport(ERROR,
                (errcode_for_file_access(),
-                errmsg("could not open tablespace directory: %m")));
+                errmsg("could not open tablespace directory \"%s\": %m",
+                       pathname)));
 
-   while ((direntry = readdir(dirdesc)) != 0)
+   while ((direntry = readdir(dirdesc)) != NULL)
    {
-       if (!strcmp(direntry->d_name, ".") || !strcmp(direntry->d_name, ".."))
+       if (strcmp(direntry->d_name, ".") == 0 ||
+           strcmp(direntry->d_name, "..") == 0)
            continue;
 
-       snprintf(pathname, MAXPGPATH, "%s/pg_tblspc/%s/%u", DataDir, direntry->d_name, (unsigned)dbOid);
+       snprintf(pathname, MAXPGPATH, "%s/pg_tblspc/%s/%u",
+                DataDir, direntry->d_name, dbOid);
        totalsize += db_dir_size(pathname);
    }
 
    FreeDir(dirdesc);
 
+   /* Complain if we found no trace of the DB at all */
    if (!totalsize)
        ereport(ERROR,
                (ERRCODE_UNDEFINED_DATABASE,
-                errmsg("Database OID %u unknown.", (unsigned)dbOid)));
+                errmsg("database with OID %u does not exist", dbOid)));
 
    return totalsize;
 }
@@ -126,7 +132,6 @@ Datum
 pg_tablespace_size(PG_FUNCTION_ARGS)
 {
     Oid tblspcOid = PG_GETARG_OID(0);
-
    char tblspcPath[MAXPGPATH];
    char pathname[MAXPGPATH];
    int64       totalsize=0;
@@ -138,23 +143,26 @@ pg_tablespace_size(PG_FUNCTION_ARGS)
    else if (tblspcOid == GLOBALTABLESPACE_OID)
        snprintf(tblspcPath, MAXPGPATH, "%s/global", DataDir);
    else
-       snprintf(tblspcPath, MAXPGPATH, "%s/pg_tblspc/%u", DataDir, (unsigned)tblspcOid);
+       snprintf(tblspcPath, MAXPGPATH, "%s/pg_tblspc/%u", DataDir, tblspcOid);
 
    dirdesc = AllocateDir(tblspcPath);
 
    if (!dirdesc)
        ereport(ERROR,
                (errcode_for_file_access(),
-                errmsg("No such tablespace OID: %u: %m", (unsigned)tblspcOid)));
+                errmsg("could not open tablespace directory \"%s\": %m",
+                       tblspcPath)));
 
-   while ((direntry = readdir(dirdesc)) != 0)
+   while ((direntry = readdir(dirdesc)) != NULL)
    {
        struct stat fst;
 
-       if (!strcmp(direntry->d_name, ".") || !strcmp(direntry->d_name, ".."))
+       if (strcmp(direntry->d_name, ".") == 0 ||
+           strcmp(direntry->d_name, "..") == 0)
            continue;
 
        snprintf(pathname, MAXPGPATH, "%s/%s", tblspcPath, direntry->d_name);
+
        if (stat(pathname, &fst) < 0)
            ereport(ERROR,
                    (errcode_for_file_access(),
@@ -172,7 +180,7 @@ pg_tablespace_size(PG_FUNCTION_ARGS)
 
 
 /*
- * calculate size of databases in all tablespaces
+ * calculate size of database in all tablespaces
  */
 Datum
 pg_database_size(PG_FUNCTION_ARGS)
@@ -182,7 +190,6 @@ pg_database_size(PG_FUNCTION_ARGS)
    PG_RETURN_INT64(calculate_database_size(dbOid));
 }
 
-
 Datum
 database_size(PG_FUNCTION_ARGS)
 {
@@ -192,11 +199,14 @@ database_size(PG_FUNCTION_ARGS)
    if (!OidIsValid(dbOid))
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_DATABASE),
-           errmsg("database \"%s\" does not exist", NameStr(*dbName))));
+                errmsg("database \"%s\" does not exist",
+                       NameStr(*dbName))));
 
    PG_RETURN_INT64(calculate_database_size(dbOid));
 }
 
+
+/* Calculate relation size given tablespace and relation OIDs */
 static int64
 calculate_relation_size(Oid tblspcOid, Oid relnodeOid)
 {
@@ -205,21 +215,27 @@ calculate_relation_size(Oid tblspcOid, Oid relnodeOid)
    char dirpath[MAXPGPATH];
    char pathname[MAXPGPATH];
 
-   if (tblspcOid == 0 || tblspcOid == DEFAULTTABLESPACE_OID)
-       snprintf(dirpath, MAXPGPATH, "%s/base/%u", DataDir, (unsigned)MyDatabaseId);
+   if (!tblspcOid)
+       tblspcOid = MyDatabaseTableSpace;
+
+   if (tblspcOid == DEFAULTTABLESPACE_OID)
+       snprintf(dirpath, MAXPGPATH, "%s/base/%u", DataDir, MyDatabaseId);
    else if (tblspcOid == GLOBALTABLESPACE_OID)
        snprintf(dirpath, MAXPGPATH, "%s/global", DataDir);
    else
-       snprintf(dirpath, MAXPGPATH, "%s/pg_tblspc/%u/%u", DataDir, (unsigned)tblspcOid, (unsigned)MyDatabaseId);
+       snprintf(dirpath, MAXPGPATH, "%s/pg_tblspc/%u/%u",
+                DataDir, tblspcOid, MyDatabaseId);
 
    for (segcount = 0 ;; segcount++)
    {
        struct stat fst;
 
        if (segcount == 0)
-           snprintf(pathname, MAXPGPATH, "%s/%u", dirpath, (unsigned) relnodeOid);
+           snprintf(pathname, MAXPGPATH, "%s/%u",
+                    dirpath, relnodeOid);
        else
-           snprintf(pathname, MAXPGPATH, "%s/%u.%u", dirpath, (unsigned) relnodeOid, segcount);
+           snprintf(pathname, MAXPGPATH, "%s/%u.%u",
+                    dirpath, relnodeOid, segcount);
 
        if (stat(pathname, &fst) < 0)
        {
@@ -243,47 +259,32 @@ Datum
 pg_relation_size(PG_FUNCTION_ARGS)
 {
    Oid         relOid=PG_GETARG_OID(0);
-
    HeapTuple   tuple;
    Form_pg_class pg_class;
    Oid         relnodeOid;
    Oid         tblspcOid;
-    char        relkind;
 
-   tuple = SearchSysCache(RELOID, ObjectIdGetDatum(relOid), 0, 0, 0);
+   tuple = SearchSysCache(RELOID,
+                          ObjectIdGetDatum(relOid),
+                          0, 0, 0);
    if (!HeapTupleIsValid(tuple))
        ereport(ERROR,
                (ERRCODE_UNDEFINED_TABLE,
-                errmsg("Relation OID %u does not exist", relOid)));
+                errmsg("relation with OID %u does not exist", relOid)));
 
    pg_class = (Form_pg_class) GETSTRUCT(tuple);
    relnodeOid = pg_class->relfilenode;
    tblspcOid = pg_class->reltablespace;
-   relkind = pg_class->relkind;
 
    ReleaseSysCache(tuple);
 
-   switch(relkind)
-   {
-       case RELKIND_INDEX:
-       case RELKIND_RELATION:
-       case RELKIND_TOASTVALUE:
-           break;
-       default:
-           ereport(ERROR,
-                   (ERRCODE_WRONG_OBJECT_TYPE,
-                    errmsg("Relation kind %d not supported", relkind)));
-   }
-
    PG_RETURN_INT64(calculate_relation_size(tblspcOid, relnodeOid));
 }
 
-
 Datum
 relation_size(PG_FUNCTION_ARGS)
 {
    text       *relname = PG_GETARG_TEXT_P(0);
-
    RangeVar   *relrv;
    Relation    relation;
    Oid         relnodeOid;
@@ -291,12 +292,12 @@ relation_size(PG_FUNCTION_ARGS)
 
    relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname,
                                                       "relation_size"));
-   relation = heap_openrv(relrv, AccessShareLock);
+   relation = relation_openrv(relrv, AccessShareLock);
 
    tblspcOid  = relation->rd_rel->reltablespace;
    relnodeOid = relation->rd_rel->relfilenode;
 
-   heap_close(relation, AccessShareLock);
+   relation_close(relation, AccessShareLock);
 
    PG_RETURN_INT64(calculate_relation_size(tblspcOid, relnodeOid));
 }
@@ -313,30 +314,36 @@ pg_size_pretty(PG_FUNCTION_ARGS)
    int64 mult=1;
 
    if (size < limit*mult)
-       snprintf(VARDATA(result), 50, INT64_FORMAT" bytes", size);
+       snprintf(VARDATA(result), 50, INT64_FORMAT" bytes",
+                size);
     else
    {
        mult *= 1024;
        if (size < limit*mult)
-            snprintf(VARDATA(result), 50, INT64_FORMAT " kB", (size+mult/2) / mult);
+            snprintf(VARDATA(result), 50, INT64_FORMAT " kB",
+                     (size+mult/2) / mult);
        else
        {
            mult *= 1024;
            if (size < limit*mult)
-               snprintf(VARDATA(result), 50, INT64_FORMAT " MB", (size+mult/2) / mult);
+               snprintf(VARDATA(result), 50, INT64_FORMAT " MB",
+                        (size+mult/2) / mult);
            else
            {
                mult *= 1024;
                if (size < limit*mult)
-                   snprintf(VARDATA(result), 50, INT64_FORMAT " GB", (size+mult/2) / mult);
+                   snprintf(VARDATA(result), 50, INT64_FORMAT " GB",
+                            (size+mult/2) / mult);
                else
                {
                    mult *= 1024;
-                   snprintf(VARDATA(result), 50, INT64_FORMAT " TB", (size+mult/2) / mult);
+                   snprintf(VARDATA(result), 50, INT64_FORMAT " TB",
+                            (size+mult/2) / mult);
                }
            }
        }
    }
+
    VARATT_SIZEP(result) = strlen(VARDATA(result)) + VARHDRSZ;
 
    PG_RETURN_TEXT_P(result);
index a4ddc7e41fdc98f3cae0cf755779fb865dbf5d12..17aeae2c04f68cec6007b2bc0cb061832f807140 100644 (file)
@@ -1,23 +1,23 @@
 CREATE FUNCTION database_size (name) RETURNS bigint
     AS 'MODULE_PATHNAME', 'database_size'
-    LANGUAGE C WITH (isstrict);
+    LANGUAGE C STRICT;
 
 CREATE FUNCTION relation_size (text) RETURNS bigint
     AS 'MODULE_PATHNAME', 'relation_size'
-    LANGUAGE C WITH (isstrict);
+    LANGUAGE C STRICT;
 
 CREATE FUNCTION pg_tablespace_size(oid) RETURNS bigint
     AS 'MODULE_PATHNAME', 'pg_tablespace_size'
-    LANGUAGE C STABLE STRICT;
+    LANGUAGE C STRICT;
 
 CREATE FUNCTION pg_database_size(oid) RETURNS bigint
     AS 'MODULE_PATHNAME', 'pg_database_size'
-    LANGUAGE C STABLE STRICT;
+    LANGUAGE C STRICT;
 
 CREATE FUNCTION pg_relation_size(oid) RETURNS bigint
     AS 'MODULE_PATHNAME', 'pg_relation_size'
-    LANGUAGE C STABLE STRICT;
+    LANGUAGE C STRICT;
 
 CREATE FUNCTION pg_size_pretty(bigint) RETURNS text
     AS 'MODULE_PATHNAME', 'pg_size_pretty'
-    LANGUAGE C STABLE STRICT;
+    LANGUAGE C STRICT;